How to Cut a Tusk Tenon Joint: Timberframe Woodworking Skills

October 5, 2019

For historical work, joist hangers won't cut it, so turn to traditional woodworking joinery

It is suitable for structural floor systems where framing needs to surround a chimney, or anywhere there needs to be an opening in a structural floor system.

The process begins with a template, especially if you're cutting more than one of these.

Make a template from 3/8 inch MDF

  • Tennon: /6 of the overall height of the timber
  • Tusk is 1/4 of the thickness of the timber.
  • The shoulder for the beveled housing is precisely in line with the tusk. This shoulder prevents the timber from rotating due to cupping or other movements.
  • Mark the timber using the template, cleaning the lines up with a framing square.
  • Cut the lines using a circular saw and a handsaw. (Make sure to cut on the right side of the line.)

Next, cut the mortise and housings for the joint.

  • Sharpen your chisel

At this point in the video, an integrated ad for SkillShare comes in (from 7:38 to 8:27). Skip it if you want to. It will not hurt our feelings.

  • Cut the tenon with a Forstner bit and then remove the excess with a sharp chisel.
  • Use a precision marking gauge to transfer the exact depth of the shoulder to the tenon board.
  • Use a sharp chisel to cut out the housing for the shoulder.
  • Clean the surfaces with a block plane and chisel.

Mark for the wedge

  • Assemble the joint and mark the tenon where it comes through the mortise.
  • Disassemble the joint and mark with a square just inside the line you just made. This will pull the joint tighter.
  • Make a hardwood wedge and then mark the top and bottom shoulders of the wedge's mortise on the tenon.
  • Drill and chop the wedge mortise.

Assemble the joint and pound the wedge in place. That's it — timber technology from our forefathers!

 

—This video is from Skill Builder, a YouTube channel that focuses on carpentry training.

 


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